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Posted to dev@tuscany.apache.org by ant elder <an...@gmail.com> on 2009/08/27 11:25:14 UTC
Endpoint registry and stopping/starting nodes
I've added a testcase in r808333 for using multiple nodes and having a
service node stopped and replaced with a new node running the service,
this should work but doesn't as the client node keeps using the
references for the original node. I'm wondering how to fix this, it
seems like the runtime should be looking up the endpoint from the
registry on each invocation, might be hard to get all the bindings
doing that but we could change the sca binding to do that. Comments
before i start doing that?
...ant
Re: Endpoint registry and stopping/starting nodes
Posted by Simon Laws <si...@googlemail.com>.
On Thu, Aug 27, 2009 at 11:01 AM, Simon Laws<si...@googlemail.com> wrote:
> Way back in the mists of time what the default binding used to do was
> trap any "target not found" type exceptions and re-resolve the
> endpoint in that case. Worked OK, easy to do and doesn't lead to a
> resolution on each call.
>
> If you catch the exception, set the EndpointReference status back to
> EndpointReference.WIRED_TARGET_NOT_FOUND and then call
> EndpointReferenceBuilderImpl.runtimeBuild(). If the result of that is
> an endpoint reference in
> EndpointReference.WIRED_TARGET_FOUND_AND_MATCHED status then retry the
> call. If not then throw a runtime exception. That should do the trick.
>
> Simon
>
I should have been a bit clearer about where this needs to happen.
Firstly down in the binding invoker you'll need to catch the protocol
specific exception and then throw something (an endpoint reference no
longer valid exception) back up to be caught in the
RuntimeWire.invoke(). From there you can reset the invocation chains
using initInvocationChains(). This in turn will call the
EndpointReferenceBuilderImpl.runtimeBuild() for you.
Simon
Re: Endpoint registry and stopping/starting nodes
Posted by ant elder <an...@apache.org>.
On Thu, Aug 27, 2009 at 12:40 PM, Simon Laws<si...@googlemail.com> wrote:
> On Thu, Aug 27, 2009 at 12:01 PM, ant elder<an...@apache.org> wrote:
>> On Thu, Aug 27, 2009 at 11:29 AM, ant elder<an...@apache.org> wrote:
>>> On Thu, Aug 27, 2009 at 11:19 AM, Simon Laws<si...@googlemail.com> wrote:
>>>>> Nothing is throwing any "target not found" type exceptions. And
>>>>
>>>> It's currently an AxisFault. To make this make sense in this special
>>>> binding.sca case you'll have to reinstate the binding.sca invoker [1]
>>>> to trap the exception and wrap it with something that the RuntimeWire
>>>> can spot.
>>>>
>>>> Simon
>>>>
>>>
>>> In the testcase this is all local with two nodes within the single jvm
>>> so using the local sca binding not the WS based one so there's no
>>> AxisFault.
>>>
>>> ...ant
>>>
>>
>> To make this a bit clearer, this is the stack trace of the reference
>> invocation just before it fails:
>>
>> Thread [main] (Suspended (breakpoint at line 42 in StatelessScopeContainer))
>> StatelessScopeContainer<KEY>.getWrapper(KEY) line: 42
>> JavaImplementationInvoker.invoke(Message) line: 100
>> PassByValueInterceptor.invoke(Message) line: 61
>> SCABindingInvoker.invoke(Message) line: 61
>> PassByValueInterceptor.invoke(Message) line: 61
>> JDKInvocationHandler.invoke(InvocationChain, Object[], RuntimeWire,
>> EndpointReference) line: 277
>> JDKInvocationHandler.invoke(Object, Method, Object[]) line: 142
>> $Proxy10.sayHello(String) line: not available
>> HelloworldImpl.sayHello(String) line: 40
>> NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not
>> available [native method]
>> NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39
>> DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25
>> Method.invoke(Object, Object...) line: 597
>> JavaImplementationInvoker.invoke(Message) line: 136
>> PassByValueInterceptor.invoke(Message) line: 61
>> SCABindingInvoker.invoke(Message) line: 61
>> PassByValueInterceptor.invoke(Message) line: 61
>> JDKInvocationHandler.invoke(InvocationChain, Object[], RuntimeWire,
>> EndpointReference) line: 277
>> JDKInvocationHandler.invoke(Object, Method, Object[]) line: 142
>> $Proxy10.sayHello(String) line: not available
>> StopStartNodesTestCaseFIXME.testCalculator() line: 76
>>
>> That scope container at the top is actually in a STOPPED state but
>> nothing in the getWrapper call path checks that so eventually it gets
>> an NPE. We could (should) change that so it notices the scope
>> container is stopped and throws an exception. The
>> SCABindingInvoker.invoke call could then catch that exception and do
>> something, I guess thats where you're suggesting inserting the
>> initInvocationChains call. If the service node has been moved from
>> being local to be remote we actually need to change the
>> SCABindingInvoker impl from being the local sca binding to be the
>> remote one. I wonder if we need a new generic SCA binding impl that
>> can handle both local and remote invocations based on whether the
>> endpoint is local or remote.
>>
>> ...ant
>>
>
> Sounds right to me. Catch the exception in the
> SCABindingInvoker.invoke and turn it into something the runtime wire
> understands. If you rebuild the chains it should rebuild the binding
> invoker etc. for you based on the configuration of the endpoint
> reference.
>
> Simon
>
Ok I've committed some changes to get that working for the
StopStartNodesTestCase. Its limited to that specific scenario and
seems quite fragile, it wont be working for different scopes,
different wiring, callbacks, non-java implementations etc, and I
expect its causing wire rebuilds when it catches exceptions for other
errors not related to the service node being restarted. I'm wondering
if it wouldn't be more robust to do the earlier suggestion of just
having the sca binding look up the endpoint from the endpoint registry
on each invocation.
...ant
Re: Endpoint registry and stopping/starting nodes
Posted by Simon Laws <si...@googlemail.com>.
On Thu, Aug 27, 2009 at 12:01 PM, ant elder<an...@apache.org> wrote:
> On Thu, Aug 27, 2009 at 11:29 AM, ant elder<an...@apache.org> wrote:
>> On Thu, Aug 27, 2009 at 11:19 AM, Simon Laws<si...@googlemail.com> wrote:
>>>> Nothing is throwing any "target not found" type exceptions. And
>>>
>>> It's currently an AxisFault. To make this make sense in this special
>>> binding.sca case you'll have to reinstate the binding.sca invoker [1]
>>> to trap the exception and wrap it with something that the RuntimeWire
>>> can spot.
>>>
>>> Simon
>>>
>>
>> In the testcase this is all local with two nodes within the single jvm
>> so using the local sca binding not the WS based one so there's no
>> AxisFault.
>>
>> ...ant
>>
>
> To make this a bit clearer, this is the stack trace of the reference
> invocation just before it fails:
>
> Thread [main] (Suspended (breakpoint at line 42 in StatelessScopeContainer))
> StatelessScopeContainer<KEY>.getWrapper(KEY) line: 42
> JavaImplementationInvoker.invoke(Message) line: 100
> PassByValueInterceptor.invoke(Message) line: 61
> SCABindingInvoker.invoke(Message) line: 61
> PassByValueInterceptor.invoke(Message) line: 61
> JDKInvocationHandler.invoke(InvocationChain, Object[], RuntimeWire,
> EndpointReference) line: 277
> JDKInvocationHandler.invoke(Object, Method, Object[]) line: 142
> $Proxy10.sayHello(String) line: not available
> HelloworldImpl.sayHello(String) line: 40
> NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not
> available [native method]
> NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39
> DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25
> Method.invoke(Object, Object...) line: 597
> JavaImplementationInvoker.invoke(Message) line: 136
> PassByValueInterceptor.invoke(Message) line: 61
> SCABindingInvoker.invoke(Message) line: 61
> PassByValueInterceptor.invoke(Message) line: 61
> JDKInvocationHandler.invoke(InvocationChain, Object[], RuntimeWire,
> EndpointReference) line: 277
> JDKInvocationHandler.invoke(Object, Method, Object[]) line: 142
> $Proxy10.sayHello(String) line: not available
> StopStartNodesTestCaseFIXME.testCalculator() line: 76
>
> That scope container at the top is actually in a STOPPED state but
> nothing in the getWrapper call path checks that so eventually it gets
> an NPE. We could (should) change that so it notices the scope
> container is stopped and throws an exception. The
> SCABindingInvoker.invoke call could then catch that exception and do
> something, I guess thats where you're suggesting inserting the
> initInvocationChains call. If the service node has been moved from
> being local to be remote we actually need to change the
> SCABindingInvoker impl from being the local sca binding to be the
> remote one. I wonder if we need a new generic SCA binding impl that
> can handle both local and remote invocations based on whether the
> endpoint is local or remote.
>
> ...ant
>
Sounds right to me. Catch the exception in the
SCABindingInvoker.invoke and turn it into something the runtime wire
understands. If you rebuild the chains it should rebuild the binding
invoker etc. for you based on the configuration of the endpoint
reference.
Simon
Re: Endpoint registry and stopping/starting nodes
Posted by ant elder <an...@apache.org>.
On Thu, Aug 27, 2009 at 11:29 AM, ant elder<an...@apache.org> wrote:
> On Thu, Aug 27, 2009 at 11:19 AM, Simon Laws<si...@googlemail.com> wrote:
>>> Nothing is throwing any "target not found" type exceptions. And
>>
>> It's currently an AxisFault. To make this make sense in this special
>> binding.sca case you'll have to reinstate the binding.sca invoker [1]
>> to trap the exception and wrap it with something that the RuntimeWire
>> can spot.
>>
>> Simon
>>
>
> In the testcase this is all local with two nodes within the single jvm
> so using the local sca binding not the WS based one so there's no
> AxisFault.
>
> ...ant
>
To make this a bit clearer, this is the stack trace of the reference
invocation just before it fails:
Thread [main] (Suspended (breakpoint at line 42 in StatelessScopeContainer))
StatelessScopeContainer<KEY>.getWrapper(KEY) line: 42
JavaImplementationInvoker.invoke(Message) line: 100
PassByValueInterceptor.invoke(Message) line: 61
SCABindingInvoker.invoke(Message) line: 61
PassByValueInterceptor.invoke(Message) line: 61
JDKInvocationHandler.invoke(InvocationChain, Object[], RuntimeWire,
EndpointReference) line: 277
JDKInvocationHandler.invoke(Object, Method, Object[]) line: 142
$Proxy10.sayHello(String) line: not available
HelloworldImpl.sayHello(String) line: 40
NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not
available [native method]
NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39
DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25
Method.invoke(Object, Object...) line: 597
JavaImplementationInvoker.invoke(Message) line: 136
PassByValueInterceptor.invoke(Message) line: 61
SCABindingInvoker.invoke(Message) line: 61
PassByValueInterceptor.invoke(Message) line: 61
JDKInvocationHandler.invoke(InvocationChain, Object[], RuntimeWire,
EndpointReference) line: 277
JDKInvocationHandler.invoke(Object, Method, Object[]) line: 142
$Proxy10.sayHello(String) line: not available
StopStartNodesTestCaseFIXME.testCalculator() line: 76
That scope container at the top is actually in a STOPPED state but
nothing in the getWrapper call path checks that so eventually it gets
an NPE. We could (should) change that so it notices the scope
container is stopped and throws an exception. The
SCABindingInvoker.invoke call could then catch that exception and do
something, I guess thats where you're suggesting inserting the
initInvocationChains call. If the service node has been moved from
being local to be remote we actually need to change the
SCABindingInvoker impl from being the local sca binding to be the
remote one. I wonder if we need a new generic SCA binding impl that
can handle both local and remote invocations based on whether the
endpoint is local or remote.
...ant
Re: Endpoint registry and stopping/starting nodes
Posted by ant elder <an...@apache.org>.
On Thu, Aug 27, 2009 at 11:19 AM, Simon Laws<si...@googlemail.com> wrote:
>> Nothing is throwing any "target not found" type exceptions. And
>
> It's currently an AxisFault. To make this make sense in this special
> binding.sca case you'll have to reinstate the binding.sca invoker [1]
> to trap the exception and wrap it with something that the RuntimeWire
> can spot.
>
> Simon
>
In the testcase this is all local with two nodes within the single jvm
so using the local sca binding not the WS based one so there's no
AxisFault.
...ant
Re: Endpoint registry and stopping/starting nodes
Posted by Simon Laws <si...@googlemail.com>.
> Nothing is throwing any "target not found" type exceptions. And
It's currently an AxisFault. To make this make sense in this special
binding.sca case you'll have to reinstate the binding.sca invoker [1]
to trap the exception and wrap it with something that the RuntimeWire
can spot.
Simon
[1] http://svn.apache.org/repos/asf/tuscany/branches/sca-java-1.x/modules/binding-sca-axis2/src/main/java/org/apache/tuscany/sca/binding/sca/axis2/impl/Axis2SCABindingInvoker.java
Re: Endpoint registry and stopping/starting nodes
Posted by ant elder <an...@apache.org>.
On Thu, Aug 27, 2009 at 11:01 AM, Simon Laws<si...@googlemail.com> wrote:
> Way back in the mists of time what the default binding used to do was
> trap any "target not found" type exceptions and re-resolve the
> endpoint in that case. Worked OK, easy to do and doesn't lead to a
> resolution on each call.
>
> If you catch the exception, set the EndpointReference status back to
> EndpointReference.WIRED_TARGET_NOT_FOUND and then call
> EndpointReferenceBuilderImpl.runtimeBuild(). If the result of that is
> an endpoint reference in
> EndpointReference.WIRED_TARGET_FOUND_AND_MATCHED status then retry the
> call. If not then throw a runtime exception. That should do the trick.
>
> Simon
>
Nothing is throwing any "target not found" type exceptions. And
doesn't the whole invocation chain need to be recalculated as for
example it could have been a node in the local JVM that was stopped
and the service restarted on a remote node?
...ant
Re: Endpoint registry and stopping/starting nodes
Posted by Simon Laws <si...@googlemail.com>.
Way back in the mists of time what the default binding used to do was
trap any "target not found" type exceptions and re-resolve the
endpoint in that case. Worked OK, easy to do and doesn't lead to a
resolution on each call.
If you catch the exception, set the EndpointReference status back to
EndpointReference.WIRED_TARGET_NOT_FOUND and then call
EndpointReferenceBuilderImpl.runtimeBuild(). If the result of that is
an endpoint reference in
EndpointReference.WIRED_TARGET_FOUND_AND_MATCHED status then retry the
call. If not then throw a runtime exception. That should do the trick.
Simon
Re: Endpoint registry and stopping/starting nodes
Posted by ant elder <an...@apache.org>.
On Thu, Aug 27, 2009 at 10:36 AM, Giorgio Zoppi<gi...@gmail.com> wrote:
> 2009/8/27 ant elder <an...@gmail.com>:
>> I've added a testcase in r808333 for using multiple nodes and having a
>> service node stopped and replaced with a new node running the service,
>> this should work but doesn't as the client node keeps using the
>> references for the original node. I'm wondering how to fix this, it
>> seems like the runtime should be looking up the endpoint from the
>> registry on each invocation.
>
> It's exactly what happens from 1.1 up to know and it's a penalty kick
> for performance. At that time i modified the node to avoid it,
> caching most recently used endpoints. Avoiding
> resolution every time. Doing resolution every time at lower level
> could mean open a socket towards the domain, so handling tcp,
> processing soap, and so on.
> It worked well in my workpool-demo apps because the working set of
> endpoint it was pretty the same, it may not work in the general case.
>
> Cheers,
> Giorgio.
>
I was thinking it would be something like the EndpointRegistry impl
managing its local copy of the endpoints it knows about and the sca
binding invoker on each invocation looking up the endpoint from the
registry. That way the binding lookup is still a quick local call and
its only the EndpointRegistry impl that has to handle keeping its
local cache up to date. Does that sound ok?
...ant
Re: Endpoint registry and stopping/starting nodes
Posted by Giorgio Zoppi <gi...@gmail.com>.
2009/8/27 ant elder <an...@gmail.com>:
> I've added a testcase in r808333 for using multiple nodes and having a
> service node stopped and replaced with a new node running the service,
> this should work but doesn't as the client node keeps using the
> references for the original node. I'm wondering how to fix this, it
> seems like the runtime should be looking up the endpoint from the
> registry on each invocation.
It's exactly what happens from 1.1 up to know and it's a penalty kick
for performance. At that time i modified the node to avoid it,
caching most recently used endpoints. Avoiding
resolution every time. Doing resolution every time at lower level
could mean open a socket towards the domain, so handling tcp,
processing soap, and so on.
It worked well in my workpool-demo apps because the working set of
endpoint it was pretty the same, it may not work in the general case.
Cheers,
Giorgio.
--
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para hacerte respirar y vivir en me.
"Favola -Moda".